Annabella was the only daughter of Sir Ralph and Judith Milbanke (later Noel). She married the poet, George Gordon Noel Byron in 1815. They had one daughter, (Augusta) Ada, born the same year. They separated in 1816 and were never reconciled. She took the name Noel when her mother died in 1822 but was always known as Lady Byron. She became Baroness Wentworth in 1856. She was a philanthropist and social reformer.